The invention relates to a composite board composed of wood material, which has the best possible strength properties. At the same time, the surface of the composite board shall be suitable for applying decorative coatings.
Composite boards composed of wood material, which are suitable for heavy loads and which can be provided with decorative surface coatings, are offered for example as PremiumBoard MFP Hybrid by Pfleiderer (Pfleiderer, PremiumBoard MFP Hybrid Brochure, published October 2013). A comparable board is offered by FINSA under the name superPan. Egger offers the Combiline board. All of these boards are composite boards composed of wood material, which have a middle layer composed of chipboard or OSB board (OSB=Oriented Strand Board). Outer layers composed of fiberboard are glued onto the middle layer, in the case of the Combiline board from Egger, very thin MDF boards (MDF=Medium-Density Fiberboard) are used. In the case of Pfleiderer, the gluing takes place by means of polyvinyl acetate glue. These boards are offered for use as supportive furniture construction boards, shelving, but also for construction purposes, above all for interior work.
These generic composite boards already have usable strength properties for the intended application areas, for example a bending strength of approx. 28 N/mm2, a transverse tensile strength of 0.5 N/mm2 and a peel strength of 0.8 N/mm2 for a 16-mm-thick board with an average bulk density of 830 kg/m3 (Pfleiderer, PremiumBoard MFP Hybrid Brochure, published October 2013). The strength of this known composite board is limited by the forces, which can receive the glued joint between middle layer and outer layer.
However, the production of the generic composite board is complicated because the gluing of the whole surface of the boards is operationally complex and it is technically difficult to ensure an even distribution of the glue over the entire surface of the middle layer or respectively outer layer to be connected. An uneven distribution of the glue leads to a qualitatively poor gluing in some areas. Moreover, the glue used to connect the outer layer with the middle layer introduces considerable amounts of liquid both into the middle layer as well as the outer layer so that a deformation of the middle layer or respectively outer layer during the hardening of the glue must be prevented.